Control and Suppression of Vortex Shedding from a Slightly Rough Circular Cylinder by a Discrete Vortex Method

Energies

卷:13

CrystianneLilian de Andrade¹  MarcosAndré de Oliveira¹  PauloGuimarães de Moraes¹  LuizAntonio Alcântara Pereira¹  AlexMendonça Bimbato² 

[1] Mechanical Engineering Institute, Federal University of Itajubá (UNIFEI), Itajubá MG 37.500-903, Brazil;

[2] School of Engineering, São Paulo State University (UNESP), Guaratinguetá SP 12.516-410, Brazil;

关键词: bluff body;    roughness model;    Venturi effect;    suppression hybrid control;    Lagrangian description;   

DOI  :  10.3390/en13174481

来源: DOAJ

【 摘 要 】

A discrete vortex method is implemented with a hybrid control technique of vortex shedding to solve the problem of the two-dimensional flow past a slightly rough circular cylinder in the vicinity of a moving wall. In the present approach, the passive control technique is inspired on the fundamental principle of surface roughness, promoting modifications on the cylinder geometry to affect the vortex shedding formation. A relative roughness size of ε*/d* = 0.001 (ε* is the average roughness and d* is the outer cylinder diameter) is chosen for the test cases. On the other hand, the active control technique uses a wall plane, which runs at the same speed as the free stream velocity to contribute with external energy affecting the fluid flow. The gap-to-diameter varies in the range from h*/d* = 0.05 to 0.80 (h* is the gap between the moving wall and the cylinder bottom). A detailed account of the time history of pressure distributions, simultaneously investigated with the time evolution of forces, Strouhal number behavior, and boundary layer separation are reported at upper-subcritical Reynolds number flows of Re = 1.0 × 10⁵. The saturation state of the numerical simulations is demonstrated through the analysis of the Strouhal number behavior obtained from temporal history of the aerodynamic loads. The present work provides an improvement in the prediction of Strouhal number than other studies no using roughness model. The aerodynamic characteristics of the cylinder, as well as the control of intermittence and complete interruption of von Kármán-type vortex shedding have been better clarified.

【 授权许可】

Unknown